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How many periods does the modern periodic table have?
AFive
BSix
CEight
DSeven
Answer & Solution
Correct answer: D. Seven
1. Periods are horizontal rows in the table.
2. Each row corresponds to one principal quantum number shell.
3. The modern table contains seven periods.
4. So the answer is seven.
_Source: NCERT Class 10 Science Ch 5 'Periodic Classification of Elements'_
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